Intervention of the Shinobi Kind
by sandewrpally
Summary: While fighting against Kaguya Naruto gets thrown to another world! After picking up some unexpected allies in the persons of Kischur Zelretch Schweinorg and Arcueid Brunestud and finishing his own fight he gets dragged into another war, but this time as master of the Fifth Grail War. Let fate be undone!


**Intervention of the Shinobi Kind**

 **A fate/stay night x Naruto fanfic**

 **By SandewrPally**

* * *

 **Prologue**

* * *

Waver was certain that he had done something in a past life to deserve having to ask the old vampire for assistance. Not only was he particularly dreading having to ask he was certain the man would milk it for his own amusement far more than help. Though he could always hope for a miracle.

The thought made Waver shake his head in exasperation. What things had been done for the pursuit of a wish, a miracle. He had done his research into the grail wars after the fourth ended. His research had revealed that not only had no one even achieved victory but that the grail itself had been tampered with in the Third! To what extent he did not know but needless to say he wondered if the fire that had immediately claimed a good portion of Fuyuki city was because of the grails corruption. As he arrived at his destination he put those thoughts to the side as he reluctantly knocked on the office of the Kischur Zelretch Schweinorg the Wizard Marshall.

"Come in!" The old vampire sounded much too chipper to the magus as he entered. He immediately became suspicious once he saw the grin that was present on the Wizard Marshalls face.

"Ah, if it isn't Lord El-Melloi II. What can I do for you on this fine day?"

Noting that he hadn't been pranked yet by being placed in a female version of himself or worse he put the file on the desk between them. Zelretch merely raised an eyebrow to silently prod Waver to continue.

"A few hours ago some of our sensors in the Clock Tower registered an abnormal amount of interference from Gaia. More so than we have ever been able to record. Even with the interference we were able to register two massive powers leaking through some something. The popular theory is a widespread reality Marble or something similar."

Zelretch was now very interested in this situation. Now many occurrences could involve both the will of the planet and the apparent size of the power being sensed. Looking at the reading he could swear he had seen something similar before…..

"The energy was neither mana nor od as well."

"I can see that." Indeed the type of power that the sensors had registered were something altogether similar but different. It was like the greater quantity of mana but the contained power of od occurring at the same time. Most magus would use Od to start a spell then mana to maintain it. The opposite was apparent for the reading he was looking at. All the energy was released with one burst with no preparation at all! He had seen this before. Where though?

Before he could sort through his memories an alarm sounded throughout his office, but the two magus' could hear it echoing throughout the hallways and other places of the tower.

" _ **All Enforcers are to report to the Observation Wing! I repeat All Enforcers are to report to the Observation Wing!"**_

Before the magus could move Zelretch had grabbed him before he found himself in front of the projected magecraft of the sensor magus. The few magus on staff flinched at the presence of the Wizard Marshall. All the while Sealing Designation Enforcers streamed in. Bazett Fraga McRemitz, one of the few enforcers to have met Zelretch before, came and stood next to him as they watched the projection.

"What do you think it is Grand Marshall?" asked the red-haired enforcer. It was almost unprecedented that all enforcers were called to come together, much less to the observation wing.

"Nothing good." Waver said as he approached one of the sensors that were unoccupied. "What the he-"

His muttering were cut off when a wave of power the likes of which none of the enforcers or other magus had felt before washed over them. Some immediately kneeled as the weight of the power made itself manifest while others had broken out into a sweat trying not to show any weakness. Throughout all this Zelretch stood still as the image cleared up to show something that finally clicked something in his memories. A name of a race of people that he had encountered when he had first started to truly master the second magic.

There projected in front of him was one of a race of dimensional travelers. One of the Otsutsuki.

From what he could see this particular one was female with while flowing hair with two brown horns growing from the top. The three eyes, two pale with veins bulging around them and a third red one on her forehead that seemed to have a rippling pattern and tomoe. She had an ethereal beauty about her that was somewhat tarnished with the rather sever scowl on her face. He assumed the reason was the young glowing man floating across from her.

Said glowing man was wreathed in golden energy from head to toe. Black lines framed part of the body while a swirl was prominent on the belly. He also noticed the tomoe adorned his body like a necklace. The young lad couldn't be more than a teenager if he wasn't immortal in some way. Zelretch could tell that the young man was on his last legs though as parts of the golden energy seemed to flicker in and out revealing tan skin underneath the energy. The Wizard Marshal knew he had to act fast before something disastrous occurred. The output of energy was more than enough for Gaia to deploy a counterforce and to have Thaumaturgy revealed to everyone.

Before everyone's eyes Zelretch reached into a portal he had created and pulled through one of the strongest beings on the planet. One Arcueid Brunestud.

"Ah, what the hell Zelretch? What was th-" the White princess of the true ancestors stopped midsentence when she noticed the serious look Zelretch sported.

"I'm sorry for interrupting whatever it was you were doing, but time is of the essence." The Wizard Marshall spoke in a commanding tone. He turned towards the gathered enforcers and let his voice carry through the small crowd. "Listen well! The beings you see before you are equivalent to gods! You will not be able to face them in a head on fight. I want barriers put up around their location as soon as we arrive. Contain the entities and suppress their power before all is lost!"

AS the enforcers prepared their magecraft Zelretch turned towards the true ancestor. He was glad she was taking this seriously though he did note the hint of excitement. "Arcueid."

"Hm?"

"I need you to engage the Otsutsuki immediately. It's obvious the boy has been fighting for a while, plus he might have information that we need."

The Moon Princess turned towards Zelretch before regarding the boy on the projection. "How powerful are these Otsutsuki? Now to mention the boy himself."

Zelretch regarded the boy himself, noting that he appeared for the most part human, if ungodly powerful. "I do not know anything about the boy but the Otsutsuki are planet destroyers, much less unique abilities that can be considered on the level of conceptual weapons or noble phantasms."

"Marshall, we're ready." Bazett called out as the crowd of enforcers readied themselves. Zelretch nodded before a massive rune appeared underneath them. The next second they disappeared with a flash as Waver regarded the projection. He knew today was going to be a bad day.

* * *

 **Break**

* * *

' _Kurama we need more chakra!"_ One Uzumaki Naruto loudly thought as he dodged another of those weird bones. He had already seen the damage even a nick could do and was not wanting to experience that anytime soon.

' _ **I know! Theres only so much power I can regain in a short amount of time! Not only that but there seems to be something in this dimension that keeps attempting to suppress our powers.'**_ His partner Kurama responded. The nine-tailed fox was constantly fighting against an oppressing force to keep them in the fight. He wondered if Kaguya herself was feeling the same presence, though doubted it all the same.

It was while Kurama was concentrating on gathering chakra that he noticed a slew of signatures pop up near them. Two stood out the most as their power was on the same scale as Naruto using both his chakra and that of Tou-san. Both combatants stopped for a moment when a many circles containing power that created a makeshift barrier, containing all three of them in it. The two signatures broke off before an older man and a beautiful young woman appeared in front of Naruto.

"What? Who are you?" the blonde Uzumaki asked as he switched his gaze between them and Kaguya. The Rabbit Goddess herself regarded the two with curiosity as she examined them with her Byakugan.

"She's even scarier up close." The young woman said. Naruto blinked before wondering what the heck these two were going to do. Were they here to help fight Against Kaguya?

"Indeed. I trust you can keep her occupied?" The older man asked. Naruto was starting to get annoyed being ignored. "While you're doing that I can hopefully get the full story from our young friend here."

"Oi! You serious?!" Both newcomers turned to look at the young man before turning back to face the Otsutsuki.

"Bit of a loudmouth isn't he?" the older man said, somewhat amused by the boys outburst.

"Pretty powerful though." The woman said as she prepared to fight the woman before her. Before she could move a sudden golden wreathed hand landed on her shoulder. She was about to reprimand the boy before a sudden well of energy was infused into her. Biting back the moan that she wanted to release she felt euphoric as the power spread throughout her body. While not a fan of the golden glowing she could tell that her abilities had been increased exponentially by whatever the boy had done.

"There, that should allow you to fight off her weird bone things. They disintegrate whatever she cuts. Her eyes allow her to see in a three hundred and sixty degree area around her." Naruto said as his golden form finally vanished, revealing the boy to be clothed in a tattered orange and black jumpsuit. The True ancestor nodded before shooting off and attacking Kaguya. As the sounds of battle intensified Zelretch turned towards the haggard blonde.

"Now then how quickly can you explain things?"

* * *

 **Break**

* * *

"Hm, quite a problem indeed." Zelretch muttered as he mulled over the information in his head. To think that a world such as the young lad's had escaped his radar for so long. No, it was more probable that whatever this Hagoromo character had prevented other members of the Otsutsuki form finding the planet. Whatever the spell or power was also prevented the second magic from finding this world. HE would honestly love the chance to see how this humanity had formed with this chakra as their main power. Luckily for everyone the sound of Arcueid's battle against Kaguya took him from his thoughts.

It was obvious that Arcueid had the upper hand in experience and skill though that did little in the face of the Otsutsuki woman's overwhelming power. It was like he was once again face to face with Brunestud. What made the situation even more complicated was that they couldn't merely kill the woman outright. From what Naruto had been able to tell he the woman had created an illusionary world by using the moon to trap everyone to convert to an army of homunculus. No telling what would happen should she activate that power and take control of Type Moon and all the other powers connected to it.

From his understanding the only way to break the spell that had been cast on Naruto's world was to once again seal Kaguya back into the moon, thereby breaking her control of the spell and releasing everyone trapped. The power to do so had been granted to Naruto and this Sasuke fellow through seals on their hands. He eyed the sun seal on Naruto's palm amazed at the intricate level of similar mage craft embedded into it. Sighing the Wizard Marshall knew he would have to attempt to locate Naruto's world while bring Kaguya and Naruto with him. Most likely Arcueid just to be safe.

"Ji-ji-san? What the matter?" Naruto asked as he attempted to recover his chakra. Like Kurama had said something seemed to be actively trying to keep his from regaining chakra. Not to mention the fact that he had an innate feeling that sage mode would be out of reach for the moment. Though it was slowly coming back he recovered as much as he could.

"Hmph. Just thinking of ways we can resolve this without more death to your people. If I can get you back to your world can you seal her for sure?" Zelretch as ked as he started to get a feel of Naruto's signature. It was easily done since the youth in question was over brimming with power.

"Yeah. She targeted me for some reason so Sasuke, Sakura and Kakashi-sensei should still be there."

The Wizard Marshall nodded as he found the dimension in question. From what little he could feel of it he concluded that Gaia's will was nonexistent leading credence to his theory that the humans were able to expand and develop their powers in ways few magus these days could accomplish. Having his spell on ready he turned to Naruto who had risen from his meditative stance. "Can you get us close to them? The spell I'm going to use will only cover a small area."

"Sure thing!" Naruto said as Kurama's chakra shroud encompassed him in gold and black before he transported both of them to a deadlocked Kaguya and Arcueid. The Otsutsuki woman could only widen her eyes as Zelretch released the spell he had prepared.

'Kaleidoscope!' in an instant the four disappeared in an instant. The surrounding magus released the barrier as some were wondering where the Wizard Marshall had taken them.

* * *

 **Battlefield of the Fourth Shinobi World War**

* * *

The three remaining members of Team Seven were tense as Sasuke attempted to find their wayward member. It was only though sealing Kaguya that they would be able to release the genjutsu that had trapped the rest of the world. As if sensing their intentions Kaguya had rushed off and transported herself away with Naruto and more than likely attempt to absorb his and the nine-tails chakra. The silence was more deafening than ever with the wasteland of a battlefield they were attempting to rest on. They remained the only people not caught in the Infinite Tsukuyomi which for Sakura meant they were the only ones left until Kaguya could be defeated.

Sasuke had offered some insight as to why the woman had taken Naruto and not him instead. With the ocular powers of his Rinnegan would allow him to return from whatever dimension he would be transported to. Something that Naruto would definitely not be able to do. It was the reason he was attempting to utilize his remaining chakra to locate Naruto and bring them back. Something had changed the Uchiha for the better as he didn't have this air of darkens around him anymore.

"Ugh!" Sasuke grunted as he collapsed to one knee. Sakura was there in an instant using her medicinal chakra to relieve the headache he had been getting searching for Naruto. "I found him."

Sakura's gasp of joy was quickly put out by his next sentence. "But for some reason I can't go there. Something is preventing me from even attempting to."

"Can you tell what it is?" Kakashi asked as he tried to recover his own chakra.

"No. It nothing chakra based either. Bu-" Before he could continue the air in front of them rippled and deposited four people. The three of team Seven instantly recognized Naruto and Kaguya. The other two were complete mysteries and people they had never seen.

The gray-haired older man was dressed in an impressive suit of black accented by gold. Pristine white cloves and a small cape the same color as the rest of his suit. In his hands was a cane that seemed to stabilize the man, but Sakura wasn't an experienced shinobi for nothing. Even if she was a naïve genin she would have been a fool not to notice the aura of power that she felt from him.

While she was wary of the older man it was the woman who stood next to Naruto. The woman was, in a few words, one of the most beautiful women she had ever laid eyes on. If she had to pick a word for it otherworldly would suit. Despite being dressed in a simply white blouse and blue skirt that extenuated her figure she could probably turn the heads of every male and some women saw her. And the power radiating off her was immense though she didn't know if it was the chakra shroud that Naruto had shared with her. Those red eyes also held something she wasn't sure to make of, though she did notice that she was facing Kaguya down with confidence she had only seen from Naruto at this point.

"Well now this brings me back." The older man said as he looked around. Sakura had a feeling he was talking about something way to far above her paygrade.

"Way to go ji-ji-san! Hey Sakura, Sasuke!" Naruto said as he waved at the both of them as if he didn't just appear out of thin air with Kaguya and two strangers. Before she could respond Kaguya had decided to make her own statement by rushing the group with her bone weapons. Before Team seven's eyes the woman managed to grip the goddess face before slamming her into the ground. Following that was a kick that sent Kaguya flying away followed quickly by the mystery woman.

"Huh. She must be more excited than I thought. Now then you know how to seal her?"

"Yeah! Me and Sasuke just have to touch her at the same time. Right?"

The last Uchiha nodded silently, wondering who the hell Naruto had made allies with in the short while he had been gone. Leave it to Naruto to make friends with perhaps the weirdest people.

"Good. I believe Arcueid can give you the perfect opportunity."

The members of Team seven merely nodded as they prepared for the final fight against Kaguya.

Hopefully.

* * *

 **So this story starts right at the end of the 4th Shinobi War and a few months before the 5th grail war. NOT really sure where to take this story to be honest but man do i research for this fanfic.**

 **Sandewrpally**


End file.
